Draft connection between towing and towed devices



Oct. 11, 1960 s. c. l -IETH 2,955,846

DRAFT CONNECTION BETWEEN TOWING AND TOWED DEVICES Filed Oct. 2. 1959'INVENTOR- $HIIRMAN C. BETH B zm w/ 'ATTORNE) ilnited States Patent DRAFTCONNECTION BETWEEN TOWING AND TOWED DEVICES Sherman C. Heth, Racine,Wis., assignor to Jacobson Manufacturing Company, Racine, Wis., acorporation of Wisconsin Filed Oct. 2, 1959, Ser. No. 844,118

7 Claims. (Cl. 280-405) This invention relates to a draft connectionbetween a towing and a towed device, and more particularly it relates toa draft connection between a lawn mower or the like and a riding sulky.

It is an object of this invention to provide a draft connection betweena towing device and a towed device wherein the connection providestraction force on the rear traction wheels of the towing device inproportion to the towing force between the two devices.

Another object of this invention is to accomplish the foregoing objectof increasing traction, but to do so without inducing a force which willtend to tip the towing device upwardly at its front end. In appreciatingthis particular object, mention is herewith made of the application ofthe invention to a lawn mower and its riding sulky, which are attachedby means of the draft connection of this invention and it should here beunderstood that a problem exists with regard to running the lawn mowerand sulky up a This particular problem is that in movin up a hill, ithas been found that some draft connections actually cause a tippingforce upwardly on the front end of the lawn mower, such that the lawnmower tends to tip backwards onto the oper-.

ator sitting in the sulky which is trailing behind the mower. Asmentioned, it is desired that the instant invention overcomes thisproblem.

Still another object of this invention is to provide a draft connectionbetween a lawn mower and its trailing sulky and to do so in aninexpensive and simplified manner. At this time, mention is made of thefact that several inventions have been made with the end result ofincreasing traction on farm tractor drive wheels, where the tractor hasa towed or trailing device draft connected thereto. However, in theseinstances, the known structures are different from that disclosed hereinand further, the point which is to be emphasized at this time is thefact that the tractor structures are necessarily more complicated andexpensive and simply do not lend themselves to the answer to the problemof providing a draft connection between a lawn mower and a riding sulky,which are considerably smaller and less expensive than the farm tractor.Also, in the present application of the draft connection, the draw barextending forwardly at the riding sulky supports the weight of the sulkyand the draw bar is thus in turn supported on the lawn mower, and thisparticular condition of supporting a weight is not generally found inthe tractor art, as in most instances the towed device isself-supporting on its own ground-engaging members such as wheels, plowblades and the like.

Other objects and advantages of this invention will become apparent uponreading the following description in conjunction with the accompanyingdrawings wherein:

Fig. 1 is a side elevational and diagrammatic view of a lawn mower andits trailing. sulky incorporating the draft connection of thisinvention.

Fig. 2 is an enlarged rear View of a portion of that shown in Fig. 1.

Patented Oct. 1 1, 1960 Fig. 3 is a sectional view taken along the line3-3 of Fig. 2, with parts added. I

Fig. 4 is a top .plan view of that shown in Fig. 3, with parts removed.

The same reference numerals refer to the same parts throughout theseveral views.

The drawings show the draft connection of this invention to be appliedbetween a lawn mower 10 and a riding sulky 11, which are respectively atowing device anda towed device. The mower 10 is generally shown toinclude ground-engaging front wheels 12 and rear traction wheels 13mounted on rear axle 14. Also, it .will be understood that an engine 16is drivingly connected in any conventional manner to the axle 14 for thepurpose of powering the traction wheels 13 to give the required forwardmotion to the unit. Also, a lawn cutter blade 17 is shown mounted on thehousing 18 of the mower 10. Further, the sulky 11 is shown to haveground engaging wheels 19 and a seat 21 is suitably mounted on the frameor draw bar 22 of the sulky 11. Of course, an operator can occupy theseat 21 and suitable steering wheel 23 is provided on the mower 10 sothat the entire rangements of lawn mower and trailing riding sulky, and,

thus no further description is necessary for a complete disclosure ofthis invention of the draft connection between the mower 10 and thesulky 11.

Figs. 2, 3 and 4 clearly show the details of this conneotion, and theyfurther orient the draft connection to the conventional parts of themower mentioned in conjunction with Fig. 1. Thus, Fig. 2 shows the mowerleft traction wheel 13 and it shows the axle housing .14, and of courseit will be understood that the driving axle extends through the housing14'for driving the wheel 13 in the usual manner, so a conventional mowerframe member 24 is shown mounted on the axle 14 by means of a plate 26and bolts 27, which all suitably secure the frame member 24 to thehousing 14. It will thus be understood that the member 24 is fixedlymounted on the mower 10 to remain in the position shown in Fig. 2, andthat is simply an upright position and further, the member 24 is shownto be an angle iron piece.

As previously mentioned, this invention relates to the draft connection,generally designated 28 and which forms I the connection between themower 10 and the sulky 11.

Thus, a pair of semicircular brackets 23 are pivotally or rotatablymounted on the axle housing 14 by means of bolts 31. The members 29 havearms or extensions 32 shown welded thereto at 36 so that the arms 32present a member or arm pivotally mounted on the axle 14 for pivotalmovement in the fore-and-aft plane of the mower 10. It will also benoticed that two other'braokets 33 are bolted to the axle 14 by means ofbolts 34 and these members 33 are fixed onto the axle 1-4 tothus presenta stop or limit for the movement of the brackets 29 axially on the axle14-.

The sulky frame or draw bar 22. includes a forward end 36, which ispivotally attached by means of pin 37 to the lower end of the arm 32.Thus, with this connection, the weight of the sulky 11 and the operatorthereon are dependent, or exerted downwardly on the axle 14 through thepivot arm 32, and this provides a desired traction force on the mowertraction wheels 13.

A tension coil spring 38 is attached at an upper end 39 to the upper endof the pivot arm 32, while the lower end 41 of the coil spring 38 isattached to a threaded link "42, which. in turn is secured by nuts 43 toa bracket 44 welded onto the draw bar end 36.

7 With the foregoing described draft connection, it will now beunderstood that the weight of the sulky and the operator thereon beardownwardly through the pin 37 This. rotation causes the spring 38 tobecome extended and thus the spring exerts an increased force betweenits mounting points on the bracket-44 and the upper end' of the arm 32.It will further be understood that the force'of the spring on the. upperend of the arm 32 is, of course directed downwardly and along the axisof the spring '38 and this force, of 'course, rcsults in a componentforce directed downwardly and onto the axle 14 to therebycincrease thetraction force on the'traction wheels 13; Itwill also be understood thatsince the arm 2,955,846 Ag a tension of said means for exerting adownward force on said rear of said towing device through said arm inresponse to increased forcejon said draw bar.v

, 2. A draft connection between a towing and a towed device, comprisingan axle disposed on said towing device transverse to the fore-and-aftaxis thereof, an arm pivotally mounted on saidaxleof said towing devicefor pivoting about the axis of said axle,-a draw bar 6n said toweddevice andbeing pivotally attached to said arm at a point thereon belowthe pivot axis of said arm, and a tensioncoil spring attached at one endto said arm at a point thereon above the pivot axis of saidarm and atthe other end to said draw bar for exerting a downward force on saidrear of said towing device 32 is pivotally or rotatably=mounted on theaxle l4, 7

there is no force created which will tend to tip the mower upwardlyatits front wheel 12, andthe only forces which can thus' act on thecaxle14 are either horizontal or vertical in the downward direction, It willbe noticed that the draft bar end 36 is angularly disposed with respectto the, horizontal center through the axle as shown in Fig. 3, suchthatthe angle is substantially less withrespect'to the'center line, thanis the angle whichthe spring 38' and the. link 42 form with the centerlinettbrough the axle 14. 'Thus, when the "draft force exerted throughthe draw,bar end'36 is increased, the downward force component exertedthrough the pin 37 is not proportionately increased since the,

draw bar 36 and lower endjof link 32 become more aligned with eachother, asthe pin 37 isrotated upwa'rdly. At the, sametime the forcev ofthe spring 38, as it is increased in length, is'transferred through theupper end of the arm 32"more directly downwardly on the axle 14 toprovide the increased traction force de sired. Expressing it a somewhatdifferent way, it should be notedthat the bracket 44, which provides theconnection point for the lower end'of the spring 38 is below the'centerline through the axle 14.- i

A stop 46 is shown weldedtothe'lower end of the angler24 and, it extendsinto the plane of "the arm 32 through said arm.-

3. A draft connection between a towing and a towed device with saidtowing device including a rear axle with traction wheels, comprising anarm pivotally mounted on said towing device at least immediatelyadjacent said rear axle of said towingfdevice for rocking movement inthe fore-and-aft plane ofsaid towing device and 7 extending in both anupper end above 'said axle and a lower end'below said axle, a draw baron said towed device and being pivotally attached to said lower end ofsaid arm to depend thereon, and anextensible force transmitting meansattached at one end to said upper end of said arm and at the other endtosaid draw bar and adapted to increase the forcettransmitted therebywhen extended for exerting a downward force on said rear axle of saidtowing device through said arm and a in response to the towing forcetransmitted'between said arm and saidtdraw bar. ,7 7

4. A draft connection between a towing andra towed device wherein saidtowing device includes a rear axle and traction rear wheels thereoncomprising an arm pivotally mounted on said rearaxle of said towing deinfront of, the lower end thereof. The arm 32 'is' thereby prevented fromrotating counterclockwise be- 'yond the position shown in Fig; 3, 'soany over-run of the sullry with respect to the mower is prevented. Also,

Fig. 4 shows the draw bar 36 to be angled to one side with respect tothe axle 14,and it will be understood thata similar construction is onthe other end of the axle 14 connected to another bar 36 which is alsosconforce on said rear'wheels. 7

nected to another rocker arm 32. Then a tie rod 47 is attached, tothemembers 32 to extend therebetween so that they pivot in unison.Shortturns or obstructions encountered by the front vehicle wheels will:not actuate only one of the arms 32 to disturb the directional controlof the vehicle. 7 t s While a specific'embodiment of this invention hasbeen shown and described it should be obvious that certain changes couldbe made in the embodiment which should 7 therefore be limited only bythe scope of the appended claims, 7 W l V r What is claimed is: p a V Vt '1. A draft connection between a towing and a'towed device, comprisingan axle mounted on saidtowing de-','

vice and extending'aboveand below said rear axle, a draw bar onsaid/towed device and being pivotally attached to said arm at a pointthereon'below the pivot axis of said arm and withrthe weight of saidtowed device being supported onrsaid arm, and a tension coil springattached at one end to said'arm at a point thereon above the "pivot'axisof said arm and'at the ,other end to said draw bar for'exerting adownwardforce on said 'rear axle of said towing devicet through said armwhen said arm is pivoted by a towing force transmitted through said drawbar to thereby increase downward traction 5. A draft connection betweenalawn mower or the like and a riding sulky' wherein the mowerincludes arear' axle with .traction wheels thereon,;comprising an pivotallymounted on said rear axle, for pivotal movement inthe foreand-aft planeof said mower or the f like,;said arm including an upper end extendingabove vice and extending .transversetto the'fore-and-aft axis thereof,an arm pivotally mounted on said axle of said a draw bar on said toweddevice and being pivotally attached to said arm at arpoint thereon belowthe pivot axis of said arm, and extensible and resilientforce trans:

mitting means being connected atone end to saidarm' towing device andextending above and belowsaid axle, f

said axle and a lower end extending below said axle, a draw bar on saidsulky pivotally 'attached to said lower end of said am for exerting adowuward'forc'e on said axle due to the weight oftsaid sulky, and atension coil spring attached at one end to said upper end of said armand attached at the other end to said'draw bar at a point below thelevel of said one end to exert a downward force on said axlethrough saidarm when the ,latter is pivoted in one direction in responseto a draftforce exerted by said draw bar on said arm.

6. A draft connection between a lawn mower or the like and a ridingsulky wherein the mower includes a rear axle with traction wheelsthereon, comprising an armtpivotally mounted on said rear axleforpivotal movement in .the fore-and-aft plane of said mower or thelike,'said arm including an upper end extending above said'axle and alower end extending below said axle, a

, draw bar on said sulky pivotally' attached; to said lower end of saidarm' for exerting a downwardforce on said axle due to the weightjof saidsulky,'a tension; coil'spring attached atone endtto said upper 'end ofsaid arm and attached at the other end to said draw bar at a point belowthe level of said one end to exert a downward force on said axle throughsaid arm when the latter is pivoted in one direction in response to adraft force exerted by said draw bar on said arm, and a stop mounted onsaid mower or the like for engaging said arm to limit pivotal movementthereof in the direction opposite to said one direction and therebylimit the forward motion of said draw bar with respect to said axle.

7. A draft connection between a lawn mower or the like and a ridingsulky wherein the mower includes a rear axle with traction wheelsthereon, comprising an arm pivotally mounted on said rear axle forpivotal movement in the fore-and-aft plane of said mower or the like,

said arm including an upper end extending above said 15 2,551,870

axle and a lower end extending below said axle, a draw bar on said snlkypivotally attached to said lower end of said arm for exerting a downwardforce on said axle due to the weight of said sulky, said draw barincluding a portion extending rearwardly from said arm and disposedbelow the level of said axle, and a tension coil spring attached at oneend to said upper end of said arm and attached at the other end to aportion of said draw bar to exert a downward force on said axle throughsaid arm when the latter is pivoted in one direction in response to adraft force exerted by said draw bar on said arm.

References Cited in the file of this patent UNITED STATES PATENTS2,540,677 Kandt et :al. Feb. 6, 1951 Bridger May 8, 1951 2,872,214 HumeFeb. 3, 1959

